Full Idea
Some artifacts are the objects of inquiry in the social sciences ...such as prehistoric tools ...and hence, artifacts are bona fide natural kinds.
Gist of Idea
Artifacts can be natural kinds, when they are the object of historical enquiry
Source
Edouard Machery (Doing Without Concepts [2009], 8.2.1)
Book Reference
Machery,Edouard: 'Doing Without Concepts' [OUP 2009], p.234
A Reaction
Presumably if a bird's nest can be a natural kind, then so can a flint axe, but then so can a mobile phone, for an urban anthropologist. 'Natural' is, to put it mildly, a tricky word.